<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>title</title>
  <style>
    body>div {
        /*width: 200px;*/
        /*height: 200px;*/
        border: 1px solid red;
        overflow: hidden;
    }
    div>div {
        width: 50px;
        height: 50px;
    }
    #d1 {
        background-color: red;
        /*float: right;*/
    }
    #d2 {
        background-color: green;
        /*float: right;*/
    }
    #d3 {
        background-color: blue;
        /*float: right;*/
    }
    ul {
        list-style-type: none;
        margin: 0px;
        padding: 0px;
    }
    li {
        float: left;
        margin-right: 20px;
    }
  </style>
</head>
<body>
<ul>
    <li>直播</li>
    <li>线上课</li>
    <li>线下课</li>
    <li>精品课</li>
    <li>白送课</li>
    <li>免费课</li>
</ul>
  <div>
    <div id="d1"></div>
    <div id="d2"></div>
    <div id="d3"></div>
  </div>
</body>
</html>